4

Configuring Networks

This chapter explains how to create unidirectional path switched ring (UPSR), linear add-drop multiplexer (ADM), and path-protected mesh network (PPMN) configurations for the Cisco ONS 15327 and how to connect ONS 15327s to Cisco ONS 15454s using these configurations. The chapter also explains how to create and edit circuits, including STS, VT1.5, multiple drop, monitor, and UPSR circuits. For procedures that create Ethernet circuits, see the "Ethernet Circuit Configurations" section on page 6-13.

4.1 Unidirectional Path Switched Rings

UPSRs provide duplicate fiber paths around the ring. Working traffic flows in one direction and protection traffic flows in the opposite direction. If a problem occurs in the working traffic path, the receiving node switches to the path coming from the opposite direction.

Figure 4-1 shows a basic UPSR configuration. If Node ID 0 sends a signal to Node ID 2, the working signal travels on the working traffic path through Node ID 1. The same signal is also sent on the protect traffic path through Node ID 3. If a fiber break occurs ( Figure 4-2), Node ID 2 switches its active receiver to the protect signal coming through Node ID 3.

Figure 4-1 Example of a basic UPSR configuration

Figure 4-2 Example of a UPSR with a fiber break

Because each traffic path is transported around the entire ring, UPSRs are best suited for networks where traffic concentrates at one or two locations and is not widely distributed. UPSR capacity is equal to its bit rate. Services can originate and terminate on the same UPSR, or they can be passed to an adjacent access or interoffice ring for transport to the service-terminating location.

Procedure: Install the OC-N Cards

Step 2 When the ACT LED turns green, log into the node. Figure 4-3 shows a sample two-node OC-48 UPSR.

Figure 4-3 Example of a two-node OC-48 UPSR

Procedure: Configure the UPSR DCC Terminations

Step 1 Log into the first node that will be in the UPSR.

Step 2 Click the Provisioning > Sonet DCC tabs.

Step 3 Under SDCC Terminations, click Create.

Step 4 On the Create SDCC Termination dialog box, press the Ctrl key and click the two slots/ports (to highlight both simultaneously) that will be the UPSR ports at the node. For example, Slot 1 (OC-48) and Port 1 and Slot 2 (OC-48) and Port 1.

Step 5 Click OK.

The slots/ports display under SDCC Terminations.

Step 6 Complete Steps 2 - 5 at each node that will be in the UPSR.

After configuring the SONET DCC, set the timing for the node. For procedures and general information about ONS 15327 timing, see the "Setting Up Timing" section on page 3-36. After configuring the timing, enable the UPSR ports.

Procedure: Enable the UPSR Ports

Step 1 From the CTC network view, open one of the UPSR nodes.

Step 2 Double-click one of the cards that you configured as an SDCC termination.

Step 3 Click the Provisioning > Line tabs.

Step 4 Under Status, select In Service for each port that you want enabled.

Step 5 Click Apply.

4.1.2 Adding and Dropping UPSR Nodes

This section provides procedures for adding and dropping nodes in an ONS 15327 UPSR configuration. To add or drop a node, you switch traffic on the affected spans to route traffic away from the area of the ring where service will be performed. Figure 4-4 shows a three-node UPSR before a fourth node is added.

Figure 4-4 Example of a three-node UPSR

Procedure: Add a UPSR Node

Note You can add only one node at a time. Perform these steps on site and not from a remote location.

Step 1 At the node that will be added to the UPSR:

(a) Verify that the optical carrier cards are installed and fiber is available to connect to the other nodes.

Step 4 Two nodes will connect directly to the new node; remove their fiber connections:

(a) Remove the east fiber connection from the node that will connect to the west port of the new node (Node 1 in the example shown in Figure 4-4).

(b) Remove the west fiber connection from the node that will connect to the east port of the new node (Node 3 in the Figure 4-4 example).

Step 5 Replace the removed fiber connections with connections from the new node. Connect the west port to the east port and the east port to the west port as shown in Figure 4-5.

Figure 4-5 A UPSR example with a fourth node

Note Perform this step on site at the new node.

Step 6 Log out of CTC and then log back in.

Step 7 Display the CTC network view. The new node should appear in the network map. Wait for a few minutes to allow all the nodes to appear.

Step 8 Click the Circuits tab and wait for all the circuits to appear, including spans. The affected circuit will display as "incomplete." One span will be missing until you update the circuit with the new node in the next step. All other spans should be present.

Step 9 In the network view, right-click the new node and choose Update Circuits with new node from the list of options. Wait for the confirmation dialog box to appear. Verify that the number of updated circuits displayed in the dialog box is correct.

Step 10 Click the Circuits tab and verify that incomplete circuits are not displayed. If incomplete circuits are displayed, repeat Step 9.

Step 11 Use the procedures in the "Switch UPSR Traffic" section to clear the protection switch and allow traffic onto the span connected to the new node.

Procedure: Drop a Node

Caution The following procedure is designed to minimize traffic outages during node deletions, but traffic will be lost when you delete and recreate circuits that passed through the deleted node.

Step 1 Use the procedures in the "Switch UPSR Traffic" section to switch traffic away from the node you are dropping. Do this for all spans connected to the node that will be deleted.

Caution Traffic is not protected during a forced protection switch.

Step 2 In the node that will be removed, delete circuits that originate or terminate in that node: (If a circuit has multiple drops, delete only the drops that terminate on this node.)

(a) Click the Circuits tab.

(b) Select the circuit(s) to delete. To select multiple circuits, press the Shift or Ctrl key.

(c) Click Delete.

(d) Click Yes when prompted.

Step 3 From the node that will be deleted, remove the east and west span fibers. At this point, the node should no longer be part of the ring.

Step 4 Reconnect the span fibers of the nodes remaining in the ring.

Step 5 Open the Alarms tab of each newly-connected node and verify that the span cards are free of alarms. Resolve any alarms before proceeding.

Step 6 One circuit at a time, delete and recreate each circuit that passed through the deleted node.

Note If the removed node was the BITS timing source, select a new node as the BITS source, or select another node as the master-timing node.

Step 7 Verify that the network map and circuits are correct:

(a) Switch to network view.

(b) Click the Circuits tab, then select each circuit and click Map.

(c) Verify that all circuits are correct and no incomplete circuits are displayed.

Procedure: Switch UPSR Traffic

Step 1 Display the CTC network view.

Step 2 Right-click the span that will be cut to add the new node and choose Circuits from the shortcut menu ( Figure 4-6).

Figure 4-6 Selecting a span for traffic switching

Step 3 On the Circuits on Span dialog box ( Figure 4-7), choose the protection from the Switch all UPSR circuits away menu:

•CLEAR—Removes a previously-set switch command.

•MANUAL—(recommended) Switches the span if the new span is error free.

•FORCE—Forces the span to switch, regardless of whether the new span is error free.

•LOCKOUT—Locks out or prevents switching to a highlighted span. (LOCKOUT is only available when Revertive traffic is enabled.)

Step 5 When the confirmation dialog box appears, click OK to confirm the protection switching. The Switch State column changes to the level of protection you chose.

Step 6 Click Close after Switch State changes.

4.1.3 Subtending Rings

Because the ONS 15327 supports up to four SONET DCCs, one ONS 15327 can terminate and groom the two UPSRs. Subtending rings from a single ONS 15327 reduce the number of shelves and cards required, and reduce external shelf-to-shelf cabling. Figure 4-8 shows an ONS 15327 with two subtending rings.

Figure 4-8 Example of an ONS 15327 with two subtending UPSRs

Procedure: Configure Subtending UPSRs

Step 1 Install the number of optical cards needed for your application.

Step 4 In the Create SDCC Termination dialog box, click the slot and port that will carry the UPSR.

Step 5 Click OK.

Step 6 Repeat Steps 5 and 6 for all optical slots/ports that will carry the UPSR.

The selected slots/ports are displayed under SDCC Terminations.

Step 7 Put the ports that you will use in service:

(a) In the node view, double-click the desired optical card.

(b) Click the Provisioning > Line tabs.

(c) Under Status, choose In Service.

(d) Click Apply.

Step 8 Repeat Step 7 for all ports/slots that will carry the UPSR.

Step 9 Follow Steps 1 - 8 for the other nodes you will use for the UPSR.

Step 10 Display the network view to view the subtending ring.

4.2 Creating a Linear ADM Configuration

You can configure ONS 15327s as a line of add/drop multiplexers (ADMs) by configuring one set of optical cards as the working path, and a second set as the protect path. Unlike rings, linear ADMs require the optical cards at each node to be in 1+1 protection to ensure that a break to the working line is automatically routed to the protect line.

shows three ONS 15327s in a linear ADM configuration. Working traffic flows from Slot 1 of Node 1 to Slot 1 of Node 2, and from Slot 2 of Node 2 to Slot 2 of Node 3. You create the protect path by placing Slot 1 in 1+1 protection with Slot 4 at Nodes 1 and 2, and Slot 2 in 1+1 protection with Slot 3 at Nodes 2 and 3.

Step 3 Set up 1+1 protection for the optical cards in the ADM. See the "Setting Up Protection Groups" section on page 3-34 for instructions. In , Slots 1 and 2 are the working ports and Slots 4 and 3 are the protect ports. In this example, you would set up one protection group for Node 1 (Slots 4 and 1), two for Node 2 (Slots 4 and 1, and 2 and 3) and one for Node 3 (Slots 2 and 3).

Step 3 Select the 1+1 protection group (that is, the group supporting the 1+1 span cards). Verify that the working slot is active. For example, under Selected Group, the working port should be shown as Working/Active. If the slot says Working/Standby, manually switch traffic to the working slot:

(a) In Operation, select Manual_Switch_to_Working. Click Apply.

(b) Click Yes in the confirmation dialog box.

(c) Verify that the working slot is carrying traffic. If it is, continue to Step (d). If not, before proceeding clear the conditions that prevent the card from carrying working traffic.

(d) In Operation, select Clear. Click Apply.

(e) Click Yes on the confirmation dialog box.

Repeat Step 3 for each group listed in Protection Groups.

Step 4 For each node, delete the 1+1 OC-N protection group that supports the linear ADM span:

(a) Click the Provisioning > Protection tabs.

(b) In Protection Groups, choose the group to be deleted (shown in Figure 4-12). Click Delete.

(c) Click Yes on the confirmation dialog box.

Figure 4-12 Deleting a protection group

Step 5 Physically remove one of the protect fibers running between the middle and end nodes. In the Figure 4-13 example, the fiber running from Slot 3, Node 2 to Slot 3, Node 3 is removed.

Figure 4-13 Converting a linear ADM configuration to a UPSR

Step 6 Physically reroute the other protect fiber so it connects the two end nodes. In the Figure 4-13 example, the fiber between Node 1, Slot 4, and Node 2, Slot 4, is rerouted so it connects Node 1, Slot 4, to Node 3, Slot 3.

Step 7 In the middle node, remove the optic cards that are no longer connected to end nodes and delete their equipment records. (If you are leaving the optic cards in place, skip this step and go to Step 9.) In this example, cards in Node 2, Slots 4 and 3 are removed:

(a) Double-click the first card (Slot 4, in the example).

(b) Click the Provisioning > Line tabs.

(c) Under Status, choose Out of Service.

(d) From the View menu, choose Go ToParent View.

(e) Right-click the card you just placed out of service (Slot 4 in the example) and choose Delete Card. (Or, you can go to the Inventory tab, choose the card, and click Delete.)

(f) Click Yes on the confirmation dialog box.

(g) Repeat steps (a) - (e) for the second card (Slot 3 in the example).

(h) Record all information for each cross-connect in the linear configuration.

Step 8 Display the node view for one of the end nodes.

Step 9 Click the Provisioning > Sonet DCC tabs.

Step 10 Under SDCC Termination, click Create.

Step 11 Highlight the slot that is not already in the SDCC Terminationlist (in this example, port 1 of Slot 1 (OC-48).

Step 12 Click OK.

Step 13 Go to the node on the opposite end (Node 3 in Figure 4-13) and repeat Steps 9 - 12.

4.3 Path-Protected Mesh Networks

ONS 15327 networks give you the option to set up path-protected mesh networks (PPMNs). PPMN extends the protection scheme of UPSR from the basic ring configuration to the meshed architecture of several interconnecting rings. Typical UPSR protection creates two separate routes between source and destination nodes on a single UPSR. PPMN does this for source and destination nodes that do not lie on the same ring but link together through a network of meshed connections. When applied to a single ring, PPMN uses the same paths as the UPSR.

PPMN connects the source and destination of a circuit over two diverse paths through a network of single or multiple meshed rings. These two routes form a circuit-level UPSR. The source sends traffic on each of the diverse routes to the destination node, where the destination node uses the active route or switches to the standby route. CTC can automatically route circuits across the PPMN, or you can manually route circuits.

Note The primary and secondary routes are guaranteed to be link and span diverse. During circuit creation, you can specify whether a node-diverse path is Required, Desired, or Don't Care: Link - Diverse Only. See the "Create a Circuit" section for more information about circuit routing options.

shows an example of a PPMN. In the example, Node 3 is allocated as the source node and Node 9 is allocated as the destination node. Automated provisioning automatically determines that the shortest route between the two end nodes passes through Node 8 and Node 7, shown by the dotted line. Cross-connections are automatically created at nodes 3, 8, 7, and 9 to provide a working-traffic route.

If you check the protected circuit box in CTC, PPMN establishes a second unique route between Nodes 3 and 9 and automatically creates cross-connections at nodes 3, 2, 1, 11, and 9, shown by the dashed line. If a signal failure occurs on the primary path, traffic switches to the second, protected circuit path. In this example, Node 9 switches from the traffic coming in from Node 7 to the traffic coming in from Node 11 and service resumes. The switch occurs within 50 milliseconds.

Figure 4-15 Example of a PPMN with ONS 15327s and ONS 15454s

PPMN also allows spans of different SONET line rates to be mixed together in "virtual rings." Figure 4-16 shows Nodes 1, 2, 3, and 4 forming a standard OC-48 ring. Nodes 5, 6, 7, and 8 link to the backbone ring through OC-12 fiber. The "virtual ring" formed by Nodes 5 - 6 - 7 - 8 uses both OC-48 and OC-12.

Figure 4-16 Example of a PPMN virtual ring

4.4 Managing Multiple ONS 15327 Rings

CTC can use topology hosts to manage multiple rings or nodes that are connected only by Ethernet and not interconnected by fiber or the DCC. Figure 4-17 shows a multiple ONS 15327 ring. An ONS 15327 with no topology host entries can only manage the node that CTC is dialed directly into and the three-node ring attached to that node. The ONS 15327 cannot manage the single node and two-node ring that are not optically connected to the dialed-into ONS 15327. Enter additional topology hosts to manage the additional single node and two-node ring.

Figure 4-17 Managing multiple rings with CTC

Procedure: Enable Multiple Ring Management

The following procedure shows how to enable CTC for multiple ring management.

•Set an attribute so that CTC routes circuits only on protected paths.

•Set a filter to prevent you from attaching circuits to unprotected cards.

•Define a secondary circuit source or destination that allows you to interoperate an ONS 15327 UPSR with third-party equipment UPSRs.

4.5.1 XTC Card Capacities

The ONS 15327 XTC cards perform the port-to-port time-division multiplexing (TDM). XTC cards perform STS and VT1.5 switching. The XTC cards support the total rearrangement of 192 bidirectional STSs from the four ONS 15327 high-speed slots, plus 12 bidirectional STSs for XTC module low-speed electrical interfaces. The XTC VT1.5 matrix supports the grooming of 336 bidirectional VT1.5 circuits that can be timselot interleaved or dropped from any port to any port within the system.

All TDM traffic consumes XTC bandwidth, even traffic that originates and terminates on the same ONS 15327. When VT1.5 circuits are routed through ONS 15327 nodes, the number of VTs used within the XTC cross-connect matrix depends on the protection scheme of the node. shows an example of VT use within an XTC at the source and drop nodes.

4.5.2 VT Tunnels

You can tunnel VT1.5 circuits through ONS 15327 nodes. VT1.5 tunnels do not use VT connection capacity, thereby freeing the VT capacity for other VT1.5 circuits.

When planning VT1.5 circuits, weigh the benefits of using tunnels with the need to maximize STS capacity. For example, a VT1.5 tunnel between Node 1 and Node 4 passing (transparently) through Node 2 and Node 3 is advantageous if:

•A full STS is used for Node 1-Node 4 VT1.5 traffic (that is, the number of VT1.5s between these nodes is close to 28),

•Node 2 or Node 3 are ONS 15454 nodes using XC cards (ONS 15454 XC cards do not have VT cross-connect), or

•Cards at Node 2 and Node 3 have reached full VT cross-connection capacity.

However, if the Node 1-Node 4 tunnel carries only a few VT1.5 circuits, creating a regular VT1.5 circuit between Nodes 1, 2, 3, and 4 might maximize STS capacity.

When you create a VT1.5 circuit, CTC checks to see whether a tunnel already exists between source and drop nodes. If a tunnel exists, CTC checks the tunnel capacity. If capacity is sufficient, CTC routes the circuit on the existing tunnel. If a tunnel does not exist, or if an existing tunnel does not have sufficient capacity, CTC displays a dialog box asking whether you want to create a tunnel. Before you create the tunnel, review the existing tunnel availability, keeping in mind future bandwidth needs. In some cases, manually routing a circuit may make more sense than creating a new tunnel.

Procedure: Create a Circuit

Step 3 In the Circuit Creation dialog box, complete the following fields:

(a) Name—Assign a name to the circuit. The name can be alphanumeric and up to 32 characters (including spaces).

(b) Type—Select the type of circuit you want to create: STS, VT (VT1.5), or VT tunnel. The circuit type you choose determines the circuit-provisioning options that display.

(c) Size—Choose the circuit size (circuit size can only be selected for an STS-type circuit).

(d) Bidirectional—Check this box if you want to create a two-way circuit; uncheck it to create a one-way circuit.

(e) Number of circuits—Type the number of circuits you want to create. If you enter more than 1, CTC returns to the Circuit Source dialog box after you create each circuit until you finish creating the number of circuits you specify here.

(f) Auto Ranged—If this box is checked, CTC automatically creates the remaining number of circuits, based on the first circuit you provisioned, by incrementing the VT or STS numbers by one each time.

(g) Protected Drops—If this box is checked, CTC only displays cards residing in 1:1 or 1+1 protection for circuit source and destination selections.

Step 4 If the circuit is on a UPSR, set the UPSR Selector Defaults:

(a) Revertive—Check this box if you want working traffic to revert to its original path when the conditions that diverted it to the protect path are repaired. If it is not checked, working traffic remains on the protect path.

(b) Reversion time—If Revertive is checked, set the reversion time. This is the amount of time that will elapse before traffic reverts back to the original working path after the conditions that caused the switch are cleared (the default is 5 minutes).

Click Use Secondary Source if you need to create a UPSR bridge/selector circuit entry point in a multivendor UPSR.

Step 7 Click Next.

Step 8 In the Circuit Destination dialog box, enter the appropriate information for the circuit destination. Click Use Secondary Destination if you need to create a UPSR bridge/selector circuit destination point in a multivendor UPSR.

Step 9 Click Next.

Step 10 Set up your circuit routing preferences.

•Route Automatically—Check this box if you want CTC to choose the circuit path automatically. If the box is not checked, you must provision the circuit spans and set the circuit paths separately.

•Fully Protected Path—Check this box if you want CTC to route circuits only on protected paths. In other words, if a path is not in a UPSR, in linear ADM mode, or path protected mesh (PPM) protected, the path cannot be used in the circuit if this box is checked.

•Node Diverse Path—Use this feature only if the nodes will be part of a PPM network. If Required is checked, a node-diverse path ensures that, except for the source and destination, the circuit's working and protect paths do not traverse the same nodes. A node-diverse path ensures that the loss of a single node will not cause the circuit to fail. If Desired is checked, CTC will route the circuit across a node-diverse path whenever possible. If a node-divers path is not available, CTC routes the circuit across the most node-diverse path possible. If Don't Care: Link Diverse Only is checked, CTC routes the circuit on the shortest path, regardless of node diversity.

Step 11 If you checked Auto-Ranged in Step 3, Route Automatically will be greyed-out and you can proceed to Step 12. If you did not check Auto-Ranged in Step 3, and you do not check Route Automatically, the Circuit Creation screen displays ( Figure 4-19). Follow Steps a - f (below) to route your circuit path manually.

Figure 4-19 Manually routing a circuit

(a) Click the line of the span that will carry the circuit (the span turns white) and move the arrow so that it points from the source to the destination. To change the direction of the arrow, click the selected line again.

(b) Click the Source STS or VT field and select the source STS or VT.

(c) Click Add Span.

The span turns blue after it is added.

(d) Verify that the spans are correctly provisioned. The spans in the Selected Spans list are the added spans.

When selecting UPSR spans, select two different paths from source to drop. In Figure 4-19, the arrows would point from rio-110 to rio-114*, rio-114* to rio-111, and from rio-110 to rio-111 (protect span).

(e) Under Selected Spans, verify that the information for the span is correct.

Note VT tunnels will be represented in the manual circuit window as a single "span" between the source and destination nodes bypassing all of the intermediate nodes. When the VT tunnel "span" is selected, CTC will use the tunnel to route the circuit through all of the intermediate spans.

(f) If the information is correct, click Finish.

Step 12 In the Confirm Circuit Creation dialog box, verify that the circuit information is correct.

Step 13 If the information is correct, click Finish.

If you entered more than 1 in the Number of Circuits field in the Circuit Attributes dialog box and the Auto-ranged checkbox was not checked, the Circuit Source dialog box displays so you can create the remaining circuits. Otherwise, you are finished provisioning the circuit.

Note Ports must be placed in service before the circuits can carry traffic.

4.5.3 Creating Circuits With Multiple Drops

Unidirectional circuits can have multiple drops for use in broadcast circuit schemes. In broadcast scenarios, one source transmits traffic to multiple destinations, but traffic is not returned back to the source.

Note When you create a unidirectional circuit, the card that does not have its backplane Rx input terminated with a valid input signal generates a loss of service (LOS) alarm.

Step 7 Verify the new drops appear under the circuit's Destinationcolumn on the Circuits window.

4.5.4 Creating Monitor Circuits

You can set up secondary circuits to monitor traffic on primary circuits. You can create monitor circuits for bidirectional circuits only. For unidirectional circuits, simply create a drop to the port where the test equipment is attached. shows an example. At Node 1, a VT1.5 circuit is dropped from Port 1 of a DS-1card. To monitor the VT1.5 traffic, test equipment is plugged into Port 2 of the DS-1 card and CTC provisioned a circuit monitor to Port 2. Circuit monitors are one-way. The monitor in shows VT1.5 traffic received by the DS-1. To monitor traffic sent from Node 1, a circuit monitor would need to be set up at Node 2.

Step 7 On the Edit Circuit dialog box, click Close. The new monitor circuit displays on the Circuits tab.

4.5.5 Editing UPSR Circuits

To change UPSR selectors and switch protection paths, use the Edit Circuits dialog box ( ). You can view the UPSR circuit's working and protection paths, edit the reversion time, edit the Signal Fail/Signal Degrade thresholds, turn PDI-P on or off, and perform maintenance switches on the circuit selector. You can also display a map of the UPSR circuits to better see circuit flow between nodes.

Figure 4-22 Editing UPSR circuits

Procedure: Edit UPSR Circuits

Step 1 Log into the source or drop node of the UPSR circuit.

Step 2 Click the Circuits tab.

Step 3 Click the circuit you want to edit, then click Edit.

Step 4 On the Edit Circuit dialog box, click the UPSR tab.

Step 5 Edit the UPSR selectors:

(a) Reversion Time—Controls whether working traffic reverts back to the working path when conditions that diverted it to the protect path are repaired. If you select Never, traffic does not revert. Selecting a time sets the amount of time that will elapse before traffic reverts to the working path following repair of the working path.

(e) Switch State—Switches circuit traffic between the working and protect paths. The color of the Working Path and Protect Path fields indicate the active path. Normally, the Working Path is green and the Protect Path is purple. If the Protect Path is green, working traffic has switched to the Protect Path.

–CLEAR—Removes a previously-set switch command

–LOCKOUT OF PROTECT—Prevents traffic from switching to the protect circuit path.

–FORCE TO WORKING—Forces traffic to switch to the working circuit path, regardless of whether the path is error free

–FORCE TO PROTECT—Forces traffic to switch to the protect circuit path, regardless of whether the path is error free

–MANUAL TO WORKING—Switches traffic to the working circuit path when the working path is error free.

–MANUAL TO PROTECT—Switches traffic to the protect circuit path when the protect path is error free.

4.6 Static Route Provisioning

The ONS 15327 uses CTC to provision static network routes in ONS 15327 network elements (NE). Static routes make it possible to have multiple CTC sessions, with different destination IP addresses, on a network of ONS 15327s that all lie on the same subnet. For example, a Network Operations Center (NOC) can remotely monitor an ONS 15327 through CTC at the same time that an on-site employee is logged into an ONS 15327 on the network with a separate CTC session. Static routes also allow workstations to connect to ONS 15327s through routers.

To achieve CTC connectivity, interconnected ONS 15327s use the Section Data Communications Channel (SDCC) for communication. SDCC communicates using a combination of the Open Shortest Path First (OSPF) routing protocol and manually-entered static routes.

CTC adds static route entries to the NE's routing table. The NE routing table information is advertised to the other ONS 15327s connected by DCCs.

To add static route provisioning on the ONS 15327, you must change the configuration of CTC workstations. An example is given below. For other typical IP addressing scenarios, see the "Common IP Addressing Scenarios with the ONS 15327" section on page 7-11. These scenarios contain additional details about router and CTC workstation setup that support the example.

Procedure: Static Routing to a Router-Linked Workstation

This procedure provisions a static route to connect an ONS 15327 through a router and to a CTC workstation. All networks in this example use a 24-bit subnet mask. The CTC workstation IP address is 192.168.100.20, the ONS 15327 IP address is 192.168.90.11, and the IP address of the router port on the same segment as the ONS 15327 is 192.168.90.1.

Step 4 In the Destination field, enter the IP address of the workstation running CTC (in this example 192.168.100.20.)

Step 5 In the Mask field, enter a 32-bit subnet mask to designate that this is a host route (in this example, 255.255.255.0).

Step 6 In the Next Hop field, enter the IP address of the router port (in this example, 172.20.222.1).

Step 7 In the Cost field enter the number of hops (in this example, 2).

To determine cost, count the number of hops between the ONS 15327 and the CTC workstation. In this example, the count is two, one hop from the ONS 15327 to the router and a second hop from the router to the CTC workstation.

Step 8 Click OK.

Step 9 To confirm that you have successfully completed the procedure, view the static route in the Static Route Window (show in ) or ping the node.

Figure 4-24 Viewing static route information

Note The Default Router entry for the ONS 15327 should be the router port (in this example, 172.20.222.1).

4.7 Connecting ONS 15327 and ONS 15454 Nodes

You can install ONS 15327 nodes into a network comprised entirely of ONS 15327 nodes or into a network that has a mix of ONS 15327 and ONS 15454 nodes. The ONS 15327 interoperates with the ONS 15454 in both linear and UPSR configurations. Because connection procedures for both types of nodes are the same (for example, adding or dropping nodes from a UPSR or linear configuration, or creating DCCs), follow the instructions in this chapter whenever you make connections between ONS 15454 and ONS 15327 nodes. Figure 4-25 shows a basic linear or UPSR connection between ONS 15327 and ONS 15454 nodes. Figure 4-26 shows a ring of ONS 15327s subtended from a ring of ONS 15454s.